Germany just got DST a minute ago when the clock jumped from 1:59.59 to 3:00.00. One hour lost ? I want my time back.

Just wait until autumn: theyâ€™ve only borrowed it â€¦ unless they switch to full-time DST before then, in which case youâ€™ll have to move to another country (anywhere tropical is highly likely to stick to standard time) in order to get your hour back. ;)

One has to pay one way or another with slow or fast clocks (relative to the Sun). Either light mornings and dark evenings or the reverse. Farther from the equator one is taxed more with the extreme seasonal variation of the length of days and nights. One could have a "midnight Sun" that might set at 1AM or have a dawn at noon where the Sun might rise at 1PM. This would be the extreme combination of being a little south of the Arctic (or north of the Antarctic) Circle and having a good-and-fast clock.

I think I have a 27hour circadian rhythm. If the world changed to a 27hour day I would probably sleep better and we certainly wouldn't have to bother with DST.

I'm with ya here. How many rockets attached to the surface of the earth and fired in the opposite direction of the earth's rotation would it take to slow the day down by three hours? And the bigger question: how much fatter would my scale think I was due to the lower centrifugal force from the slower-spinning Earth? (My guess is that, despite the 1,000 mph the Earth spins at the equator, it's not flinging us out as much as you'd think--after all, I don't feel any more weighed down way up here than I did when I was visiting the homeland of Arecibo in November--and that's more than a 40-degree difference in latitude.)

I'm sure there would be horrendous environmental impacts to doing this, but I know my body clock would be much happier with the longer day. I might finally be able to get a full night's sleep without having to oversleep to get it...

(For the sake of my self-image, I probably shouldn't post such ignorant drivel in the presence of the high proportion of S@Hers who are physicists, but oh well...)

I think I have a 27hour circadian rhythm. If the world changed to a 27hour day I would probably sleep better and we certainly wouldn't have to bother with DST.

Isn't that just being called a night-owl? Or just normal for geek programmers?

;-)

I'm with ya here. How many rockets attached to the surface of the earth and fired in the opposite direction of the earth's rotation would it take to slow the day down by three hours?

Just wait a while and the moon and tides will do that for you.

Shame however that we'll lose the spectacle of the eclipses.

And the bigger question: how much fatter would my scale think I was due to the lower centrifugal force from the slower-spinning Earth? (My guess is that, despite the 1,000 mph the Earth spins at the equator, it's not flinging us out as much as you'd think

It certainly helps rockets up into orbit!

I'm sure there would be horrendous environmental impacts to doing this,...

I'm not so sure... It's an interesting question as to how the weather would be affected. My initial guess is that we would suffer increased development of rain clouds and stronger storms due to the longer day adding more solar energy into any dark clouds that develop. A good question for over at CPDN...

And the bigger question: how much fatter would my scale think I was due to the lower centrifugal force from the slower-spinning Earth? (My guess is that, despite the 1,000 mph the Earth spins at the equator, it's not flinging us out as much as you'd think

IIRC you weigh about a KG less at the equator than at the poles, because the Earth is a Oblate spheroid (your further from the center.)

As for the rockets, isn't that like the closed box of flying birds don't weigh less. The rockets pushing the air cancel each other.

For the record, I simply just pulled out my calculator and came up with the number Y2.00719178K for the title of this thread, which I personally feel is the most elegant, if not also fairly accurate way of depicting this particular event. If this "name" hasn't been used elsewhere before, then I claim all creative rights.

Huh? Not MAPLE, Mathematica, Matlab or Derive?!? LOL.

As for categorizing songs, I have this odd penchant for knowing the exact length of every song in my album collection to the second. This kind of number memory came in handy during my college radio days, like when I needed a song that was, say, exactly 5:48 long to end out my radio shift at exactly three hours. Otherwise, it's a useless skill that I could do without, and as I get older I'm less able to do so (I blame CDs - the song lengths are randomly placed on the packaging if anywhere, unlike record albums which always had them on the album itself). I can't remember phone numbers or famous irrational numbers to the Nth digit. Those are completely random, meaningless values. I only can remember "data" i.e., the cost of something I bought 10 years ago, or the length of a song, etc.

- Matt

Here at the SETI@Home message boards, we do not blame CDs. By now, we all know who/what to blame. ;)Capitalize on this good fortune, one word can bring you round ... changes.

I think I have a 27hour circadian rhythm. If the world changed to a 27hour day I would probably sleep better and we certainly wouldn't have to bother with DST.

I'm with ya here. How many rockets attached to the surface of the earth and fired in the opposite direction of the earth's rotation would it take to slow the day down by three hours? And the bigger question: how much fatter would my scale think I was due to the lower centrifugal force from the slower-spinning Earth? (My guess is that, despite the 1,000 mph the Earth spins at the equator, it's not flinging us out as much as you'd think--after all, I don't feel any more weighed down way up here than I did when I was visiting the homeland of Arecibo in November--and that's more than a 40-degree difference in latitude.)

I'm sure there would be horrendous environmental impacts to doing this, but I know my body clock would be much happier with the longer day. I might finally be able to get a full night's sleep without having to oversleep to get it...

(For the sake of my self-image, I probably shouldn't post such ignorant drivel in the presence of the high proportion of S@Hers who are physicists, but oh well...)

That stuff can be figured out. One could calculate the mass of the Earth, its effective radius and, by using E = 1/2*m*v^2, calculate its rotational energy, or mv for its rotational momentum. I believe centrifugal acceleration is v^2 / r. Right now I don't have time to figure it out. The average density of the Earth is about 5.5 grams per cubic centimeter, but there is some mass concentration at the core which would reduce the effective radius a little.

If you've got a 27 hour cycle, your day is going to slide around the clock.

If you wake up at 9:00pm one night, midnight the next, then 3:00am, then 6:00am, then 9:00am -- by the end of the week you're not a night owl, you're sleeping in.

:-)

That is exactly what happens when I'm not working and in school (i.e. no real-world schedules to interfere with my sleep patterns--the first night, I may start to feel tired and therefore go to bed at around, oh, 11:00pm. The next day, I don't really feel tired until 2:00am. The next night, it wouldn't be impossible for me to not feel tired until 5:00am. Given a week, I could actually turn into a (gasp) morning person!

IIRC you weigh about a KG less at the equator than at the poles, because the Earth is a Oblate spheroid (your further from the center.)

If youâ€™re measuring in kilograms, your â€œweightâ€ is constant, regardless of where you areâ€”they represent mass.

But at the equator, the combination of the Earthâ€™s rotation with the greater distance from the centre (offset a little by the bulge) reduces the force of gravity by about half a percent as compared to that at the poles. If I weighed myself on a spring-scale calibrated at the North Pole, it would read about 0.3 kg light at the equator. (Note that a balance-beamâ€™s reading would be unchanged, ignoring any temperature or air-pressure effects.)

As for the rockets, isn't that like the closed box of flying birds don't weigh less. The rockets pushing the air cancel each other.

Not the same at all. If rockets needed anything to push against, they wouldnâ€™t work in space. True, the exhaust creates some â€˜windâ€™ in the opposite direction, but most of its work is done at the throat of the nozzle, and the remaining energy is rapidly soaked up by dissipative forces. Moreover, the atmosphere is very fluid, so is incapable of imparting significant momentum to the continents.

Which raises another issue: considering that the mantle is also fluid, albeit extremely viscous, the rockets might have undesirable consequences WRT accelerating â€œcontinental driftâ€, triggering earthquakes and vulcanism at the plate margins.

All we have to do to get a longer day is wait a few million years; the Earthâ€™s rotation is gradually slowing as tidal interactions transfer rotational energy to the Moonâ€™s orbit.

And the bigger question: how much fatter would my scale think I was due to the lower centrifugal force from the slower-spinning Earth? (My guess is that, despite the 1,000 mph the Earth spins at the equator, it's not flinging us out as much as you'd think--after all, I don't feel any more weighed down way up here than I did when I was visiting the homeland of Arecibo in November--and that's more than a 40-degree difference in latitude.)

Not much. Earth's gravity gives acceleration at roughly 9.81 metres per square second while centripetal force at equator gives acceleration at roughly 0.0338 metres per square second (just took it out of my bc). The later one being 0 at the poles of course. Which is roughly 0.34% or a quarter of a kilogram for average human being.
That's approximately half a pound if a pound is the weight of a pint of beer ;)

[edit]The effect of earth's rotation on weight of a mass is directly proportional to the cosine of latitude. Additionally it causes lateral force on body - pushing it towards equator. This effect, however, is rather small and easily masked off by effect of drinking too many pints of beer ;) Metod ...

Near the poles one is closer to the center of the Earth, increasing gravitational attraction. Also there's no or little centrifugal force. Near the equator both centrifugal force and being farther from the center of the Earth diminish what the scales register on a given mass. It's probably this centrifugal force that makes the Earth oblate in the first place. Maybe the degree of oblateness is proportional to the centrifugal force but that is a guess. I remember from an old reference that the polar diameter of Earth is about 7900 miles and the equatorial diameter, 7927 miles.

I get 0.03391 m/s^2 centrifugal acceleration at the equator factoring in 366.24 revolutions per year sidereally, or 0.003458 g. 7927/7900 is about 1.003418, which is awfully close to unity plus the centrifugal acceleration in gs. So it's possible that oblateness might have something to do with centrifugal force / gravitational force. I don't know whether trying this on Jupiter or Saturn would work or not. There is the problem of extreme mass variation throughout those planets. If someone is 1/3 percent farther from a mass concentration the gravity is 2/3 percent less due to falloff being as the square of the distance. This might suggest that someone weighing 100 kilograms at the poles would weigh only 99 kilograms at the equator (2/3 percent falloff + 1/3 percent centrifugal force). But Earth is not a point mass concentration so this may not be correct. I don't know what a plumb bob does at temperate latitudes. Does it hang exactly vertically? (90 degrees from the horizon). Even the horizon is depressed but (I believe) refracted upward by the air. If a star becomes visible on the horizon it's 34 minutes below the horizon. But is the apparent horizon exactly 90 degrees from the zenith or nadir? The altitude of the eyes changes this, of course.

If I recall correctly (it has been quite a while), as long as the center of mass is a particular distance away, and the object is spherical, it does not matter what size the sphere is as long as the radius of the sphere does not exceed the distance from the center of mass to the nearest point of the other object.

Spherical shells of different mass densities all look like a mass at a single point from outside of the outermost sphere.BOINC WIKI

If youâ€™re measuring in kilograms, your â€œweightâ€ is constant, regardless of where you areâ€”they represent mass.

Nearly...
If measuring mass, it doesn't matter what units of mass you use. Measuring in pounds or tons is just as correct as tonnes, kilograms or grams (but don't forget the conversion constants!).

No argument here. My point was that kilograms can only measure mass (the existence of the bastard unit â€œkilograms-forceâ€ notwithstanding), not that you canâ€™t measure mass in any other units. OTOH the pound can refer to either mass or force, depending on context. (The poundal, one pound-foot per second per second, is rarely used.)

"weight" is "mass" times (opposed) "gravitational attractive force". Mass remains constant whilst your weight depends on how you are attracted to what is supporting you.

"weight" is in effect a special assumed case of "force = mass * acceleration"

Yes and no. Technically speaking, â€œweightâ€ should always be a force, but as used in common parlance the term refers to what a physicist would call â€œmassâ€ at least as often as not. If Alcan finds that a shipment of Jamaican bauxite unloaded at Kitimat is short, I don't think they'd accept the explanation that the weight was correct at the latitude it was shipped from! A silly example, perhaps, but the point is that most of the time we mean by "weight" an invariant property thatâ€™s independent of local circumstances, viz mass. Likewise â€œto weighâ€ something usually means to determine its mass, although the method used may well involve comparing gravitational forces.